What would give my better performence i7 3820 overclock

Hello everybody, I have a small question, what would give me the best overclock performance, lets say till 4.3ghz.
I mean id I let the mem around 1600mhz wil I get more performance true overclocking with the bclk ore with just the multiplier.
Higher blclk wil give my a higher bandwith

Bandwidth really isn't an issue in most cases. That said, test it out and see which way is the best for how you use your computer...